Flying shear



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Patented Feb. 9, 1937 UNITED .STATES PATENT OFFICE FLYING SHEAR,

Englewood, N. J.

Application February 26, 1934, Serial No."l12,938

' Renewed July 9, 1936 46 Claims.

This invention relates to machines for cutting moving stock of various kinds and compositions, and particularly to flying shears adapted for cutting strip or sheet metal coming from a rolling mill, but the invention is not limited to such use. i

An object of the inventionis to provide a flying shear in which a cutting knife damaged during the operation of the flying shear can be replaced with a new knife without stopping the shear and without interfering with the delivery of the material. It is an object of the invention to change knives quickly and thereby limit the length of material which passes through the shear during the knife-changing operation. According to one feature of the invention the knife changing is entirely automatic and controlled by electric means which detects a damaged knife. by its imperfect cutting action.

Another object of the invention is to provide a flying shear with automatic control means for causing the knives to shear the strip material immediately after the passage of an irregular front end, and to continue to shear the strip, as it comes from the mill, into desired lengths. The invention provides novel control means for shearing off an irregular front or rear end of a strip and thereafter throwing the knife drums into a non-shearing position and holding them in such position, or for obtaining automatic or manual control of subsequent shearing. operations, or automatic starting or stopping of the shearing operations by the knife drums when the end of a strip enters or leaves the flying shear.

Another object of the invention is to provide improved mechanism for driving the various parts of the shear, including novel means for accelerating or decelerating the drums to strip speed, and for causing relative movement of the drums toward and from one another to make a cut. The driving mechanism includes two sets of gearing between the knife drums and feed rolls of the shear, and mechanism by which the speed of one set of gearing can be either added to or subtracted from that of the other set to obtain a great number of speed ratios between the knife drums and feed rolls for cutting strips of different lengths.

The novel mechanism of this invention for accelerating or decelerating the knife drums con-- verts a constant rotative speed of the drum driving arms-into a variable drum speed which synchronizes the knife speed with the strip speed at the instant the cut is made. Relative movement of the knife drums toward and from one another to make a cut is produced by a novel combination of eccentrics which obtains rapid movement of the knives and a short radius of gyration for the operating parts and a balancing of the load to be moved.

Another object of the invention is to provide novel control mechanism including a swinging finder containing a photo tube which is influenced by the presence or absence of light along the path over which the finder swings. In this invention such finders detect the passage of an irregular front or rear end, and detect a damaged knife by its failure to completely sever the strip.

Other objects, features and advantages of the invention will appear or be pointed out as the specification proceeds.

In the accompanying drawings, forming part hereof:

Fig. 1 is a diagrammatic view, mostly in section, showing a flying shear embodying the in- 5 vention.

Fig. 2 is an enlarged side elevation of the flying shear shown in Fig. 1, looking toward the left.

Fig. 3 is a sectional view on the line 3-3 of Fig. 2. Figs. 4 and 5 are enlarged sectional views on the lines 4-4 and 5-5 in Figs. 2 and 3, respectively.

Fig. 6 is a sectional view on-the line 6-6 of Fi 2. Fig. 7 is a vertical sectional view through the upper knife drum and its driving mechanism.

Figs. 8 and 9 are enlarged sectional views on the lines 8-8 and 9-9, respectively, of Fig. 7.

Fig. 10 is an end view taken on the line Ill-Ill of Fig. 7.

Fig. 11 is a bottom plan view of the structure shown in Fig. 10.

Fig. 12 is an enlarged fragmentary detail view of one of the knives.

Fig. 13 is an end view of the differential unit for changing from one set of knives to the other.

Fig. 14 is a sectional view on the line I 4- of Fig. 13.

Fig. 15 is a fragmentary elevation showing the 50 latching drum of the differential unit of Figs. 13 and 14.

Fig.1: is a sectional view taken on the line |6-|6 of Fig. 15.

Fig. 17 is a sectional view through one of the latching drums, the section being taken on the line of Fig. 14.

Fig. 18 is a fragmentary horizontal sectional view of a portion of the brake and latch mechamsm.

'* Figs. 19 and 20 are enlarged sectional views taken on the lines |9-| 9 and 28-28, respectively, of Figs. 13 and. 19, respectively.

Fig. 21 is an enlarged sectional view taken on the line 2|-2| of Fig. 1.

Fig. 22 is an enlarged sectional view taken on the line 22-22 of Fig. 1, and is also a sectional view taken on the line 22-22 of Fig. 23.

Fig. 23 is a sectional view taken on the line 23-23 of Fig. 22.

Fig. 24 is a vertical sectional view of one of the knife drums.

Fig. 25 is an enlarged detail view showing the connection of one of the knives to the drum.

Fig. 26 is a fragmentary vertical sectional view through the flying shear and feed means with the apparatus for detecting incomplete cuts and for finding the full width of the sheet when making front and rear end cuts.

Fig. 27 is an enlarged view of a portion of the switch mechanism.

Fig. 28 is an enlarged end view of one of the swinging finders shown in Fig. 26.

Fig. 29 is a sectional View taken on the line 29-29 of Fig. 28.

Fig. 30 is a plan view of the material as it comes from the mill, showing typical irregular front and rear ends.

Fig. 31 is an enlarged view of the motor and op-- erating connections of the looping unit shown in Fig. 26.

Figs. 32 and 33 are enlarged views,-partly in section, taken along the lines 32-32 and 33-33, respectively, in Fig. 26.

Fig. 34 is an enlarged sectional view showing some of the driving gears of Fig. 1.

Fig. 35 is a sectional view taken on the line 35-35 of Fig. 34.

Fig. 36 is an enlarged sectional view of a part of the control mechanism shown in Fig. 1.

Fig. 37 is an enlarged view of one of the gear changing mechanisms shown in Fig. 1.

Figs. 38 and 39 are end and top plan views, respectively, of the gear changing mechanism shown in Fig. 3'7.

Figs. 40 and 41 are diagrams showing the changes in the peripheral speed of the knife drums when driving with the mechanism shown in Figs. 8 and 9, respectively.

Fig. 42 is a schematic view of the control devices with their electric circuits.

Fig. 43 is a sectional view along the line 43-43 of Fig. 42.

Fig.44 is a sectional view taken on the line 44-44 of Fig. 43.

Referring to Fig. 1, the flying shear has knife drums 5| and 52 operatively connected by gears 53 and 54 to run at the same speed. These drums constitute rotary knife-carriers. The knife drum 5| rotates in hearings in slides 55 and 55 at op posite ends of the drum. The knife drum 52 rotates in bearings in slides 56'and 56. All of these slides are vertically movable in guideways in a main frame 51.

Sheet material is supplied to the flying shear by feed rolls 68 and 6| having their opposite ends journaled in bearing blocks 62 and 63. The blocks 62 are movable in slots in a supporting frame 64, and a spring 65 is held against the bearing blocks 62 by a screw 68. The spring 65 urges the roll 60 toward the roll 6| and the tension of the spring can be varied by turning the screw 66, which threads through the top of the frame 64.

The knife drums 5|, 52 and feed rolls 6!], 6| are rotated by a common motor 61, which is coupled to a shaft 68. A fiy-wheel 69 and pinion 10 turn with the shaft 68.

The motor 61 drives the knife drums 5| and 52 through a gear 1| meshing with the pinion l0 and connected by a shaft 12 with a pinion 13 which drives a gear 14 secured to a drive shaft 15.

A shaft 16 is supported by bearing blocks and extends through the hollow interior of the knife drum 52. A spindle 18 has universal jaws 19 at its opposite ends connecting it with a-shaft 80 and the shaft 16, respectively. The driving connections between the shaft 16 and the knife drum 52 will be explained in detail in the description of Figs. 7-11. The shaft 80 is connected with the drive shaft 15 by a coupling unit 8|.

The upper knife drum 5| is driven from a shaft 82 which extends through the upper knife drum and is supported in bearing blocks 83. A spindle 84 has universal jaws 85 at its opposite ends connecting it with the shaft 82 and a shaft 86, respectively, the latter shaft being driven from the coupling unit 8| through a coupling unit 81. These coupling units 8| and 81 have gears 88 and 89, respectively, which mesh with one another, and these units will be explained in detail in describing Figs. 22 and 23.

When the shears are used to cut lengths equal to the circumference of the knife drums 5|, 52, the drums are rotated at a uniform speed with the peripheral speed of the knife drums equal to the lineal speed of the sheet material through the feed rolls and shear. When the lengths to be sheared are greater or less than the circumference of the knife drums, these drums are rotated at a variable speed so that the speed of the knives is equal to that of the sheet material atthe time of shearing, but less or greater during the remaining part of each revolution.

This variable rotative speed of the knife drums is obtained by moving the bearing blocks 11 and 83 vertically so that the axes of the shafts l6 and 82 are slightly above or below the axes of the knife drums. The driving connections between the shafts I6 and 82 and the knife drums 5| and 52, respectively, have a novel crank movement which'produces the variable rotative speed of the knife drums, as will be more fully considered in connection with Figs. 40 and 41 of the drawings.

The mechanism for moving the bearing blocks 11 and 83 vertically will be explained in the description of Figs. 2-4.

The knife drums are moved toward one another when knife blades on the drums are in position to shear the material, by eccentrics which turn in timed relation to the knife drums and move the slides 55' and 56 vertically in opposite directions. The gears 53 and 54 are designed to operate with variations in the distance between their axes.

An eccentric 92 extends through the lower end of each of the slides 56 and 56' and rotation of these eccentrics causes vertical movement of the slides 56 and 56 and knife drum 52. Each of the eccentrics 92 is integral or rigidly connected with a short shaft 93. Each of these shafts 93 has a gear 94 through which the shafts are driven by gears 95 (Fig. 2) on a driving shaft 93.

' Referring again to, Fig. 1, the slides 55 and 55 are moved vertically by eccentrics 91 on short shafts 98, which are rotated by gears 99 from the driving shaft 96.

Each of the short shafts 93 is journaled in a yoke I 0|, and each of the short shafts 98 is journaled in a yoke I02. The lower ends of the yokes IOI and I02 cooperate with timing eccentrics I03 and I04, respectively, and these timing eccentrics cause a vertical up and down move-' ment of the yokes, shafts 93 and 98, and the eccentrics carried by them. The timing eccentrics I03 and I04 are integral or connected with shafts I06, which turn in hearings in the frame of the machine and are connected together at the center of the machine by a coupling I01. One of the shafts I06 is coupled to a driving shaft I03.

The shaft 96 is driven through a couplingconnecting it directly to'a shaft H0, and power from this shaft II 0 is transmitted to the eccentricdriving shaft I09 through gears III and I I2.

' These gears have a speed ratio of 2 to 1 so that the shaft H0 turns twice as fast as theeccentric driving shaft I08. This gear ratio is illustrative and other ratios may be used with shears designed to cut a different range of lengths.

The eccentrics move one knife drum up at the same time-that they move the other knife drum down so that the load on the eccentric driving mechanism is mostly a friction load, because the weight of one knife drum is balanced against the weight of the other.

The combination of two eccentrics for operatthis invention. In order to produce with a'single cam the fast acceleration of the knives toward and from one another which is obtained by the combined action of two eccentrics, it would be necessary to use a very steep cam and the load would be further from the axis of rotation and require greater driving torque. I v

A shaft H5 drives the shaft H0 through a differential unit H0. The construction and operation of this unit will be explained later. The function of this unit is to change knives and this is accomplished by ca sing relative rotation of the shafts H5 and H0 through the correct angle which will change the relation of the angular positions of the eccentrics with respect to the angular positions of the knife drums so that the eccentrics bring the drums together when different knives are in-cutting position.

Gears I I 0-I2I on the shaft H5 each have a clutch by which they can be connected to the shaft us. A clutch handle 122 is shown in its middle neutral position in Fig. 1. With the clutch handle in this position the gears H8 and H9 are both free to turn independently of the shaft H5.

is clutched to the shaft H5 atany time, the

choice depending on the desired gear ratio between the motor 01 and the shaft H5.

The gears II8-I2I mesh with gears I I20, respectively, on a shaft I which is'driven from the shaft l2rthrough gears I3I and I32.

The gearratio between the motor 61 and the knife drums is constant, and therefore the speed ratio between the knife drums and the eccentrics depends upon which of the. gears II8I2I is clutched to the shaft H5. When the gear H8 is clutched to the shaft I I5 in Fig. 1, the knife drums make one revolution while .the timing eccentrics I03 and I04 make one revolution.

When the gear H9 is clutched to the shaft I I5, the knife drums make one and one-half revolutions for each revolution of the timing eccentrics. When driving the shaft I I5 through the gears I20 and I2I, the knife drums make two and two and one-half revolutions, respectively, for each revolution of the timing eccentrics I03 and I04.

The knife drums are brought together to shear the material once with each revolution of the timing eccentrics I03 and I04. There are four knives evenly. spaced around the circumference of each knife drum. When the drums are making 1 or 2 revolutions for each revolution of the timing eccentrics, the same knives'will be in shearing position each time the drums are brought together to make a out. When the drums are making 1 or 2% revolutions between each shearing operation the cuts will be made alternately with opposite knives, as for example, with the first and third knives of each drum.

The shear may be set up to cut with the first knife, or first and third knives, depending on the speed ratio used, On none of the available speed ratios willthe second or fourth knives come into use when the shear is set up to cut with the odd numbered knives. If the first or third knife on either drum breaks orbecomes defective, so that the-material is notcut across its entire width, automatic means, which will be explained hereinafter, operate the differential unit H6 to change the relative positions of the timing eccentrics and knife drums so that the eccentrics move the drruns together to shear'the material when the second or fourthknives of the drums are in shearing position. This knife-changing operation is performed quickly while the shear is running. After changing to the new knife, the shear continues to cut sheets of the same length as were cut by the first knife.

The feed rolls 60 and 6| are driven from the motor 61 through gear mechanisms which make it possible to change the gear ratio between the motor 61 and the feed rolls by very small increments through a wide range, and these increments are uniform over the whole cutting range of the shear. Since the gear ratio between the motor 61 and the knife drums 5|, 52 is constant, the gear changing mechanism between the motor 67 and the feed rolls 60, 6| changes the speed ratio be-v tween the knifedrums and the feed rolls and determines the length of material passing between the drums for each shearing operation. The flying shear shown in the drawings can be set to cut sheets of any length between ten and twenty-five feet by increments of one-eighth inch. The feed roll 0| is coupled to a driving shaft I 35, and the feed 'roll 60 is driven from this driving Referring again' to Fig. 1, the shaft I4! is driven by the shaft I30 through two sets of bevel gears I50 and I5I and a connecting shaft I52.

The ringgear I45 meshes with a gear I54 fixed to a shaft I55. The shaft I55 is driven from a 35 shaft I66 through a reverse gear I51, and the shaft I56 is connected with a gear shaft I58 by differential gearing I59. This differential gearing is similar in construction to the differential gearing I42 and includes a bevel gear fixed on the shaft I56, a ring gear I68, and a bevel gear fixed to the gear shaft I58. A set of gears I62, of different sizes, is fastened to the gear shaft I58.

The ring gear I69 is driven by a gear I68 on a shaft I64, which is driven through a reverse gear I65 by a gear shaft I66. A set of different size gears I 61 is fixed on the gear shaft I66.

The set of gears I61 is rotated from a shaft I68 ahrough a gear I69 splined on the shaft I68 and an idler I10. The idler I18 is carried by an axle extending from an arm I1I which is slidable and rotatable on the shaft I68. The arm I'll extends on both sides of the gear I69 and has a handle I12 by which it is moved to bring the idler W8 into mesh with any one of the gears I61. This mechanism is shown more completely in Figs. 37-39, and will be more fully explained in describing those views. I

The set of gears I62 is driven from a shaft I14 by a splined gear and idler I15 similar to the gear mechanism between the set of gears I61 and. the shaft I68 already described.

There are two gears I16 and I11 on the shaft I14, and either of these gears can be clutched to the shaft I14 by operating a clutch handle I18. These gears I16 and I11 are driven by gears fixed on a shaft I19, which is operatively connected with the shaft I68 through countershafts I89 and IM and the connecting gears shown in Fig. 1. The shaft I19 is driven from the gear shaft II through a gear train I82.

The shaft I41 has a fixed gear ratio with the knife drums, and when the ring gear I45 is stationary, the shaft I35 turns in the opposite direction and at the same speed as the shaft I61, and the feed rolls 6| and 69 run at the same speed as the shaft I41. By rotating the ring gear I45 in one direction or the other the speed of the shaft I35 is made greater or less than that of the shaft I41, and the ratio of the feed roll speed to that of the knife drums is changed so that more or less sheet material passes between the knife drums for each shearing operation. The reverse gears I51 and I65 make it possible to use the mechanism which drives the gear I54 toprotate the ring gear I45 either way and add to 6r subtract from the speed of the shaft I35.

The speeds of the knife drums and feed rolls are proportioned so that the exact length of material to be sheared is delivered by the feed rolls while the knife drums turn through 1, 1%, 2 or 2% revolutions. The drums are in cutting position on multiples of /2 revolution and when cutting sheets of any desired length the gearing is set to cause the knife drums to make. the number of half revolutions which causes the peripheral speed of the knife drums to most nearly equal the lineal speed of the strip through the feed rolls 60 and 6 I. For example, if the circumference of the knife drums is ten'feet and sheets of ten foot length are to be cut, the gearing is set so that the knife drums make one revolution while ten feet of strip passes through the feed rolls.

If sheets eleven or twelve feet long are to be cut, the gears are set so that eleven and twelve feet of strip, respectively, pass through the feed rolls for each revolution of the knife drums. When cutting sheets thirteen feet long, however, the peripheral speed of the knife drums more nearly ing block 11.

rotation of the gears I93, I94

approximates that of the strip if the drums make 1. /2 revolutions while thirteen feet of strip material pass through the feed rolls. When cutting twelve and one-half foot sheets there is no preference between one and one and one-half drum revolutions for twelve and one-half feet of strip passing through the feed rolls, because the peripheral drum speed is just as far removed from the strip speed in either case.

For sheets between twelve and one-half and seventeen and one-half feet long, the knife drums make 1% revolutions while the length of strip to be cut passes through the feed rolls. When cut-. ting sheets between seventeen and one-half and twenty-two and one-half feet long, the knife drums make 2 revolutions while the length of I material to be cut passes through the feed rolls.

The strip material can pass freely between the knife drums when they are separated, but it is necessary that the knives and strip be moving at the same speed during the actual shearing operation. When cutting ten, fifteen, twenty and twenty-five foot lengths, the knife drums rotate at constant speed, making 1, 1%, 2 and 2 /2 revolutions, respectively, while the length of material to be cut passes through the feed rolls. For all other sheet lengths it is necessary to increase or decrease the drum speed to that of the strip during that part of the drum revolution when the knives come together to make the cut.

Variable knife drum velocities are obtained by moving the axes of the shafts 16 and 82 out of coincidence with the axes of their respective knife drums 52 and SL The mechanism for raising and lowering the shafts 16 and 82 is shown in Figs. 1-4. Each of thebearing blocks 11 has a screw I84 which is non-rotatably connected to the bearing block, as shown in Fig. 4. The lower end of the screw threads into a sleeve I85, rotatably supported in a cross head I86, and connected by a bolt I81 to a bracket I88 which extends out from the slide 56. The sleeve I85 is free to rotate with respect to the bolt I81.

A gear I89 is splined on the sleeve I85 and is located in a slot I99 in the cross head I86, so that the sides of the slot prevent axial movement of the gear. When the gear I89 turns the sleeve I85, the screw I84 is moved up or down, depending on the direction of rotation of the gear and sleeve, and raises or lowers the bearing block 11.

The bearing blocks 83 each have two rods I92 which extend down on opposite sides of the bear- These rods I92 have their lower ends threaded into sleeves in the cross head I86, the construction being similar to that shown in Fig. 4. Gears I93 and I94, which raise and lower the rods I92, mesh with the gear I89, as shown in Fig. 2. The gears I93 and I94 turn in the same direction as one another and in the opposite direction to the gear I89. The screw I 84 has the same threads as the rods I92 so that the and I89 causes the blocks 11 and 83 to move in the opposite direction.

The gears I93, I94 and I89 are rotated by a gear I96 which meshes with the gear I94, and is keyed to a shaft I95 on the cross head I86. A Worm wheel I96, keyed to the shaft I95, is rotated by a worm I91 on a shaft I98, best shown in Fig. 5. i The mechanism thus far described for moving the bearing blocks 11 and 8 3 is the same on both sides of the machine. The two shafts I98 (Fig. 1) are connected together at the center of the machine by a coupling I99 so that the mechanisms on both sides work together. A hand-wheel 209 is fastened to the end of the right-hand shaft I98,

and this hand-wheel is used by the operator to adjust the positions of the shafts" and 82.

A pointer 20l operating over a scale 202 just above the hand-wheel indicates the-position of the shafts. The scale is attached to the main frame 5! and the pointer MI is pivoted on a stud 203 extending from the main frame. One end of the pointer is forked and fits over a pin 204 carried by the block 11. Vertical movement of this pin 204 with the block TI operates the pointer.

Fig. 7 is a section through the upper knife drum 5|. The right-hand bearing of this knife drum comprises a housing 200 for the driving" arms by which the, shaft 82 rotates the knife drum. There is a web 201 on the inside of the housing 206, and this web has driving lugs 208 on its right side and driving lugs 209 on its left side.

A sleeve 2|0 on the shaft 82 is prevented from turning on the shaft by keys 2 (Figs. 7-9), but is movable axially along the shaft. Driving arms 212 and H3 are integral or rigidly connected to the sleeve 2l0. There are two driving arms 2l2 (Fig. 8) and each has a roller 2I4 for contacting with the adjacent driving lug 208. The rollers 2 are diametrically opposite one another with respect to the shaft 82.

Shock absorbers prevent the driving arm rollers 2 M from coming against the driving lugs 208 with violent impact. Each of these shock absorbers includes a roller 2l5 carried by one end of a bell crank 2l6, which is pivoted to the driving lug 208. A rod 2H pivoted to the other end of the bell crank 2l6 extends into a cylinder 2|8. The head of this cylinder has a pivot connection 2|.9 with 2. lug on the inside of the housing 206. A coil spring 220 is compressed between one end of the cylinder 2l8 and a collar on the rod 2 ll.

When the rollers 2l4 are not in contact with the driving lugs 208, the springs 220 hold the bell cranks 2 IS in such positions that the driving arm rollers 2, as they move toward the driving bn cranks 215 by the driving arm rollers 2H reduces the moment arms of the springs 220 and consequently reduces the force from the springs on the driving arms.

When the axis of the shaft 82 coincides with the axis of the knife drum, the rollers 2I4 both contact with the driving lugs 208 and transmit rotary movement of the shaft 82 to the knife drum without change of speed. If through manufacturing inaccuracy one roller 2! is slightly ahead of the other, it contacts with one of the driving lugs ,duringthe entire rotation of the shaft 82 and transmits the constant speed rotation of the shaft to the knife drum.

When the axis of the shaft 82 is higher, and

' farther from the cutting knife than the axis of the knife drum, one of the driving arms 2|2 transmits the rotary movement of the shaft 82 to the knife drum during /2 revolution and the other driving arm transmits the movement during the next half revolution. Sincethe distance from the axis of the knife drum to 'theFpoint of A contact of the driving roller 2 on the driving lug 208 changes as the shaft 82 turns, the angular speed of the motion transmitted to the knife drum is variable. The greater the eccentricity of the shaft 82 in the knife drum, the greater the variations in the speed at which the knife drum is rotated.

The driving lug faces with which the rollers 2 l 4 contact are cam faces, and the variations in drum speed for a given eccentricity of the shaft 82 depend on the shape of these faces, particularly their slope with respect to radii from the axis of the knife drum.

The variations in the drumspeed for maximum eccentricity of the shaft 82, and with the shaft in a position equivalent to one-half of its maximum.

eccentricity, are shown in Figs. 40 and 41, and this variable speed operation will .be more fully described in the explanation of those views.

The arms 2l3 have rollers 222 which contact with cam faces on the driving lugs 209 to transmit rotary movement of the shaft 82 to the knife drum. The driving arms 2I2 and 2l3 are spaced axially on the sleeve 2I0 so that when the driving arms 2 l2 are in position to contact with the driving lugs 208 the driving arms 2l3 are far enough to the left in Fig. 7 to rotate without coming 'in contact with the driving lugs 209.

The knife drum is driven by the driving arms 2|2 when the average peripheral speed of the drum is less than the lineal speed of the strip, and it is therefore necessary to speed up the drum for each shearing operation. When the average drum speed is higher than the strip speed, the driving arms 2|3 are used to rotate the drum so that it slows down for each shearing operation.

The sleeve 2I0 is-shifted axially to the right in Fig. 7 to shift the drum drive from the driving arms 2| 2 and their cooperating lugs shown in Fig. 8 to the driving arms H3 and lugs 209' shown in Fig. 9.

-An S-link 224 has one end pivoted at 225 to each of the lugs 209. The other end of each link 224' is connected with the housing 206 by a toggle link 2215, thecenter pivot of which is connected with a rod 22! extending into 2. cylinder 228 similar to the cylinder 220 shown in section in Fig. 8. A roller 229 carried by each link 224 contacts with one of the driving arm rollers 222,,and in combination with its connected links and a spring in the cylinder 228 serves as a shock absorber for preventing the driving arm roller 222 from coming against the. driving lug with violent impact.

The mechanism for moving the sleeve 2| 0 to shift from the drum drive mechanism of Fig. 8 to that shown in Fig. 9 includes rods 230 which have their ends threaded through the driving arms 2 I3. These rods extend along opposite sides of theshaft 82 to the left end of the drum in Fig. 7 where they pass through the opposite sides of a double arm 232, best shown in Figs. 10 and 11.

A bevel gear 233 on the end of each rod 230 meshes with a bevel gear 234 on one end of a short shaft 235 extending through a bracket on the double arm 232. 235 has a square end for receiving a wrench. The double arm 232 is keyed to the shaft 82 and turns as a unit with the shaft.

Gears 236 fixed on the rods 230 mesh with an idler gear 231 on the shaft 82. Rotary movement of either of the rods 230 in either direc-- tion is transmitted through the idler gear 231 to the other rod 230.

The bevel gear 233 fixed on each rod 238 against one face of the double arm 232, and a collar 238 fixed on the rod against the opposite face of the double arm, prevent axial movement of the rod. Since these rods 238 can not move axially with respect to the shaft 82, their rotation causesthe sleeve 210 to be. shifted along the shaft in one direction or the other, depending on the direction of rotation of the rods.

Fig. 12 is an enlarged fragmentary view of one of the knives. The knife has a taper or rake so that as it comes into shearing relation with the cooperating knife on the other drum it shears the material first at the left or high side of the knife and then progressively across the width of the material as the knife drums move closer together. This progressive cut reduces the load which is imposed on the driving mechanism when shearing the material as compared with a flat knife which cuts the full width at the same time. The fast and extensive knife drum movement obtained by the double eccentricsof this invention makes it possible to shear the material progressively and still obtain a small bite angle. The bite angle is the angle through which the knife drums turn during the shearing operation.

Figs. 13 and 14 show the construction of the differential unit 6 (Fig. 1) by which the angular positions of the knife drums with respect to the eccentrics are changed to cause the eccentrics to bring the drums together to shear with different knives from those originally chosen before starting the shear. Fig. 14 shows the shafts H0 and H5 extending through bearings in the rotatable housing of the differential unit with bevel gears 240 and MI, respectively, fixed on the ends of these shafts inside the housing. These bevel gears 246 and 241 mesh with idler gears 242 carried by the rotatable housing which corresponds to the ring gear of an ordinary automotive difierential. A brake 243 is applied to the shaft I l ii-whenever power is supplied to the solenoid which operates this brake.

The differential unit has a removable side 244,

which is tightly closed to retain lubricant within the housing. Brake drums 245 and 246 are formed on the right and left ends, respectively of the housing. The brake drum 245 has recesses in which latching blocks 241 (Fig. 17) are secured in position to receive a latch for stopping and holding the brake drum and differential unit in theposition which gives the correct relation between the knife drums and eccentrics when knives I and 3 are to be used for shearing.

The brake drum 246 is slotted and has latch blocks 249 (Fig. 16) for receiving a latch to stop and hold the brake drum and differential unit in the correct position for cutting with knives 2 and 4 of the knife drums. The latch blocks 249 are not connected directly to the brake drum 246, but are bolted to a drum 250 which is located inside of the brake drum and rotatable with respect to the brake drumabout the axis of the differential unit. The drum 250 is connected to the housing of the differential unit by a bolt 25I which extends through an arcuate slot 252. A worm 253 is fixed on a shaft 254 which turns in lugs 255 extending from the brake drum 246. This shaft has square ends for receiving a tool. The worm engages teeth of a worm-wheel segment 256 extending from the drum 250. When the bolt 25! is tight, the drum 258 is rigidly connected with the housing and the brake drum 246. When the bolt 25! is loosened, the shaft 254 and worm 253 can be rotated to change the angular relation of the drum 256 and brake drum 246.

In order to prevent a latch from dropping into the slot in the brake drum 246 before reaching the latch block 249, central wings 258 extend from both the front and back of the latch block. The slot in the brake drum has narrow extensions at both ends. These extensions are wide enough to receive the wings 258, but too narrow for the latch to enter.

The friction brakes for the drum 250 are shown best in Fig. 13. There is similar mechanism for the brake drum 245. Brake levers 260 and 26I have pivot connections with lugs of a base 262. Brake shoes 263 and 264 have pivot connections with the brake levers 260 and 261, respectively. Screws 266 threading through the brake levers and contacting with the brake shoes hold these shoes in such positions that they contact the drum with substantially uniform pressure when applied, and do not drag on the drum when released.

The top ends of the brake levers are drawn together to apply. the brake by a bell-crank 268 pivoted between its ends to the brake lever 260 and having one end connected to the brake lever 26| by a link 269.

The bell-crank 268 is connected with a plunger 210 by a pin extending through a substantially horizontal slot in the bell-crank. A solenoid 21! has its armature connected with the bell-crank 268 by a link 212.

An electric contact 213 is carried on the lower end of a rod which is connected to one end of the bell-crank 268 by a link 214. A second electric contact 215 is held against the contact 213 by a spring 216. This second contact is connected with a dash-pot 211 which delays the upward movement and causes the contacts to remain apart for a period when movement of the bellcrank 268 causes the contact 213 to move upward away from the contact 215.

A latch 288 is moved toward and from the brake drum 246 by a toggle 281. The joint of the toggle is connected with the lower end of the plunger 21!] by a link. 282. The plunger 210 has a flange 283 just above its connection with the link 282. A telescopic link 284 is connected at its upper end to the joint of the toggle 281 and at its lower end to a. lug on the base 262. A spring compressed in the telescopic link 284 urges the joint of the toggle 28l upward to straighten the toggle and move the latch 280 into the recessed latching blocks of the drum 246. When the solenoid 21f is energized it moves the parts into the positions shown in Fig. 13, so that the latch 288 is withdrawn from the brake drum and the brake released.

A spring 285 between the brake lever 260and the fixed frame of the machine absorbs the shock from the latch 288 when it-drops into a recess in the brake drum 246. When the latch 280 brings the brake drum and differential unit to rest, the force of impact is transmitted from the latch to the brake lever 260, by which the latch is supported, and tends to rock the brake lever counter-clockwise about its pivot connection with the frame 262. The spring 285 resists such movement of the brake lever, but yields to absorb the shock.

The brake mechanism for the brake drum 245 is the same as the structure shown in Fig. 13. Certain differences, not shown in this view, between the respective brake mechanisms for the drums 245 and 246 will be explained in describing Fig. 19.

Fig. 18 is a horizontal sectional view showing the latch and toggle for the brake 'drum 245. This view has been turned around with respect to Fig. 13, but the latch 28'! and toggle 288 shown in Fig. 18 correspond to the latch "280 and toggle 28| in Fig. 13.

Fig. 19 shows the mechanism for holding the brake released from the brake drum 246. A locking fork 290 extends over the flange 283 and prevents the plunger 210 from being moved up. A compression spring 29| urges the fork 290 into the locking position shown in Fig. 19. The locking fork is withdrawn against the pressure of this spring 29f when the brake is to be applied. A solenoid 292 furnishesthe power for withdrawing the locking fork 290. This solenoid has. an armature 293 connected with the locking fork by a bell-crank 294.

A latching pin 296 is urgedv downward by a spring 291 and rests on a collar 298 near the endof the locking fork, but when the locking fork moves to the left in Fig. 19 far enough to permit the plunger 210 to rise, the collar 298 moves be-' yond the latching pin 296 so that it drops down behind the collar and prevents the spring 29| from moving the locking fork back after the, supply of power to the solenoid 292 is cut off.

The mechanism which operates the brake for the drum 245 issimilar to that shown in Fig. 19, but it has a solenoid 300 for raising the latching pin which corresponds with the latching pin 296 and it has no solenoid 292 for withdrawing the locking fork which holds the brake released.

Fig. 21 is a sectional view through the dif-- ferential unit I42 of Fig. 1. The entire gear housing rotates as a unit with the ring gear I45 and serves as a tight enclosure for lubricant in. which the bevel gears and idlers run.

Figs. 22 and 23 are enlarged sectional views of the coupling unit 81 shown in Fig. 1. A wormwheel 302 is fastened on the end of the shaft 86 and is connected with the gear 88 by bolts303 which extend through arcuate slots 304 in the worm-wheel. When these bolts 303 are tight, the gear 88 and worm-wheel 302 turn as a unit, but when these bolts are loosened the worm-wheel and gear can be moved angularly with respect to one another within the limits imposed by the length of the slots 304. I

l A worm' 306 is fixed to a shaft 301 journaled in lugs 308 extending from the'gear 88. The worm 306 meshes with the worm wheel 302, and the ends of theshaft 301 are square so that a wrench can be applied to this shaft to turn the worm wheel and accurately control the relative movement of the gear and worm wheel. The gear 88 is fixed to a supporting shaft 309 supported in suitable bearings.

The coupling unit 8| (Fig. 1) is the same as the coupling unit 81 shown in Figs. 22 and 23, and is adjusted to determine the relative angular positions of the shafts l5 and 80. The adjustment provided for by these coupling units 8| and 81 is necessary to obtain the correct relation between the angular positions of the knife drums and eccentrics because this relation is altered when the bearing blocks TI and 83 are moved to change the eccentricity of the shafts l6 and 82 with respect to the axes of the drums. After the shafts I0 and 82 are set for a given eccentricity, and before the shear is started, the coupling units 8| and 071 are adjusted, with the eccentrics in the positions occupied at the time of shearing, to

3 l3 by which the knives are fastened to the drum.

In addition to screws 3|3, the knives are held in place by wedge blocks 3|4 and these wedge blocks are connected to the drum by screws 3|5.

Fig. 26 is a vertical sectional view showing some of the control mechanism. Sheet material from a rolling mill 3|8 passes through a chute 3l9 and then over a looper unit 320 and through pinch rolls 32| and 322.

The looper unit includes a roller 323 carried at the end of arms 324 which are supported for oscillation about the axis of the roll 322. A variable torque gear motor 325 has a crank 326 connected with the arms 324 by a link 321. The motor 325 has a strong brake 328 which is applied when the current to the motor 325 is out off, and magnetically released when current is' supplied to the motor. A side elevation of the torque gear motor 325 is shown in Fig. 31.

Referring again to Fig. 26, the variable torque gear motor 325 urges the roller 323 upward toward the position indicated in dot-and-dash lines and lifts the portion of strip material 330 between the rolling mill and the pinch rolls to maintain a uniform tension in the strip as it passes from the rolling mill to the pinch rolls.

A bell crank 332 has a pivot connection 333 with the pinch roll supporting frame 334, and a roller 335 at one end of the bell crank runs on the surface of the pinch roll 32| and is held against the pinch roll bya spring 336. The upper end of the bell crank 332 carries contacts 331 and 338 on its opposite sides. These contacts are insulated from, but resiliently connected with, the bell crank by structure which will be described in the explanation of Fig. 2'7.

When there is no sheet, material between the pinch rolls, the upper roll 32| contacts with the lower roll 322, and the bell crank 332 occupies the position shown in Fig. 26. When the bell crank 332 is in this position the contact 331 closes a circuit between separate contact members carried by a bracket on the pinch roll supporting frame. As soon as strip material enters the pinch rolls it causes the upper roll 32| to rise from the lower roll 322 by a distance equal to the thickness of the strip. This movement rocks the bell crank 332 clockwise in Fig. 26 and the small movement of the upper pinch roll is multiplied by the long lever arm of the bell crank by which the contacts 331 and 338 are carried. This movement of the bell crank causes the contact 33.! to move away from its adjacent contact members; and causes the contact 338 on the other side of the bell crank to move into position to close a circuit between contact members carried by a bracket 340. Thus the bell crank 332 operates to close one circuit when there is no. material in thepinch rolls and another circuit when there is material between these rolls.

' Fig. 32 is a view, mostly in section, showing a gear motor 342 for driving the pinch rolls and a spring 343 pressing against bearing blocks 344, in which the upper pinch roll 32| is journaled, to maintain a pressure between the pinch rolls. This pressure is controlled by a screw 345 which threads through the pinch roll supporting frame 334 and loads the spring 343.

Referring again to Fig. 26, the strip material passes from the pinch rolls 321' and 322 to the feed rolls 60 and 61. The strip is supported between the pinch rolls and feed rolls by a chute 341 which has sides 348 which are movable toward and from one another by screws 349 (Fig. 33) to accommodate the chute for strips of different width. The screws 349 are turned by hand wheels 350.

The front and rear ends of a strip delivered from the rolling mill are always of irregular shape. Fig. 30 shows typical front and rear ends 352 and 353 of the strip 330. A device for finding the full width of the strip is located behind the pinch rolls and ahead of the feed rolls. This device for determining when the irregular front or rear edge has passed includes a luminous tube 355 (Figs. 26 and 33), such as a mercury vapor lamp, located beneath a slot in the bottom of the chute 341 and extending the full width of the chute. I

Lamps 351 are carried by the sides of the chute. These lamps are slightly higher than the luminous tube 355 and directly above it when the sides of the chute are brought together to accommodate strips narrower than the full width of the chute. Opaque shields 359 connected to the sides extend under the lamps 351 and prevent light from the luminous tube 355 from shining up through the recesses in which the lamps 351 are located.

There aretwo finders 361 and 362 supported by a frame 363 for swinging movementabove the luminous tube 355. oscillated between the two extreme positions indicated by dot-and-dash lines in Fig, 23. The finder 361 has an upwardly extending arm 365. A gear motor 366 has a crank arm 361 connected with the arm 365 by a link 368. Rotation of the crank arm 361 causes the finder 361 to swing back and forth over the luminous tube 355, and the pivot connection of the arm 365 to the link 368 can set at different positions along slots in the arm and link to control the angle through which the finder 361 swings. The finder 362 is oscillated by a gear motor 311 through link connection similar to those for the finder 361.

The pivot connection between the arm 365 and the link 368 is adjusted in accordance with the width of the strip to be cut so that when the finder 361 is at one end of its angle of movement it is in line with the lamp 351 and when at the touches separate contacts 314 and closes a circuit slots for the lever 365 and barrel 380.

between them. A contact 315 on the finder 362 closes a circuit between contacts 311 when the finder 362 reaches the limit of its inward-swing. Both of the motors 366 and 311 have magnetically operated brakes 318 which release when current is supplied to the motors 366 and 311, but stop the motors almost instantly when the power to these motors is cut off.

Figs. 28 and 29 are enlarged views of the swinging finder 361. This finder has a barrel 380, through which light from the luminous tube or lamp passes to a lens 381 which converges the light on a photo tube 382. The body of the finder, which surrounds the photo tube, is a cylinder 384 open at both ends. This cylinder turns in ball bearings 385 in a housing 386, which has The housing of the finder is closed at one end by a cover plate 361 and at the other end by a relay box 388 on which the-finder is supported.

A photo electric relay unit closes a circuit when The finders 361 and 362 are the light from the tube 355 and lamp 351 is cut off by the strip material passing over the tube 355. The finders 361 and 362 can not swing to their extreme inner positions and close the circuits across the contact members 314 and 311 unless the strip covers the full length of the luminous tube 355 between the opaque screens 359. Therefore the closing of these circuits indicates 'that the irregular end has passed the luminous tube 355.

Referring again to Fig. 26, bottom guides 394 and 395 are located on the entry and delivery sides of the shear and connected to the shear frame 51 by bolts extending through slots in brackets 396 and 391 which permit limited vertical adjustment of the positions of these guides 394 and 395 with respect to the passof the knife drums. A top guide- 398 is connected to the shear frame by bolts extending through a slotted bracket 399.

A delivery table 401 has rollers 402 which are driven at a peripheral speed greater than the speed of the strip material through the shear. There is some slippage between the rollers 402 and the material resting on them before it is cut from the strip. When a predetermined length of strip has passed between the knife drums, they are brought together to shear the strip and the rollers 402 cause the severed sheet to increase its speed of travel so that it pulls away from the strip and leaves a gap of increasing width between the sheared edges.

If the knife is broken or becomes defective, so that the material is not completely sheared across its entire width, the sheet can not pull away from the strip and there is no gap as in the case of a complete cut. The presence or absence of this gap controls the knife-changing mechanism. Any time that this gap between a cut sheet of predetermined length and the strip ma-- terial fails to appear when due, the mechanism automatically changes to the other set of knives.

A swinging finder 404, similar in construction to the finder shown in Figs. 28 and 29, is supported by the frame close to the upper knife drum on the delivery side of the shear. This finder 404 has an upwardly extending slotted arm 405, which has a pivot connection with a link 406.

Crank arms 401 and 408 are rigidly connected to a shaft 409 (Figs. 1 and 26) which is supported in bearing brackets 410 carried by the frame 51. The crank arm 401 has a pivot connection with the link 406, which is slotted so that the pivot connection with the crank arm can be set in different positions along the link. The crank arm 408 contacts with the surface of the knife drum 51 just beyond the ends of the knives.

When the upper knife drum 51 moves down to make a cut, the crank arms 401 and 408 turn counter-clockwise and cause the finder 404 to swing counter-clockwise into the position shown in Fig. 26. When the drum 51 moves up again after a shearing operation, the crank arms 401 and 468 turn clockwise and swing the finder 404 clockwise until a contact 412 on the finder touches separate contact members 413 and closes the circuit between them.

There are four lights under the swinging finder 404. One of these lights is a lamp 415 located under an opening in the bottom guide 395. Another lamp 416 is located above the strip material which passes through the shear and in radial alinement with the lamp 415 with respect to the swinging finder. Arcuate luminous tubes 411 and 418 on opposite sides of the lamp 416 and along the path of the swinging finder 404 supply light to the finder at all times except when it is swinging over the lamps M5 and 4 I6.

When the knife drum 5| is moving down to make a cut, and the finder 464 is swinging counterclockwise, the lamp M6 is lighted and the entire path of the finder is illuminated. When the knife drum M is moving up after making a cut, and the finder 404 is swinging clockwise, the lamp 4I6 is out and the lamp M5 is lighted. If the cut is complete and the sheet severed from the strip moves faster than the strip and creates a widening gap between the severed edges as above described, then this gap permits light from the lamp M5 to reach the swinging finder which operates in such relation to the knife drums that it swings across the lamp 4I5 at the time when the gap is due to pass over this lamp.

When the sheet is completely severed by the shearing operation and the gap occurs as described, the finder 404 has its path illuminated during its entire clockwise movement. If a knife breaks or becomes defective so that the shearing operation does not completely sever, the sheet, there will be no gap through which the light from lamp 4I5 can reach the swinging finder. When this occurs, no light reaches the finder during its clockwise movement over the lamps M5 and M6, and the period of darkness causes the photo tube in the finder to set the control mechanism in operation to change the relation between the knife drums and eccentrics so that other knives on the drums are usedv for cutting.

Fig. 27 is a detail view showing the connection of the contact 337 to the bellcrank 332. The contact 33! is connected by screws to a block of insulation 420, and this block is screwed to a square plunger 42 I which extends through the bifurcated upper end of the bell crank 332. A spring 422 compressed between a portion. of the bell crank 332 and a shoulder of the plunger 42I urges the plunger into the position shown in Fig. 27, but permits the contact 331 to yield when it comes against the adjacent contact members carried by the pinch roll supporting frame 334. A pin 423 limits the movement of the plunger 428 to the left in Fig. 27.

Figs. 34 and 35 show the clutch mechanism for connecting gear H6 or II!) with the shaft M5. A sleeve 425 splined on the shaft H5 can be shifted from the center position shown in Fig. 34 to either the right or left to clutch gears H9 or M4, respectively, to the shaft I I5. The sleeve 425 has clutch jaws 426 adjacent either end for engaging clutch jaws 421 on the hubs of the gears.

The sleeve 425 is shifted by a yoke on the end of the handle I22. The handle extends through a slot in a plate 429 and is held in set position by a square plunger 436 which has a forked end adapted to straddle the handle I22, as shown in Fig. 35, to hold the handle in neutral position. The plunger 43!] is pushed back from the slot against the tension of a spring 43I when the handle I22 is to be shifted in either direction, and the plunger is permitted to move forward again over the slot and holds the handle at either end of the slot. Numerals 432 on the plate 423 indicate the correct position for the handle I22 for cutting a given length of sheet.

The clutch mechanism operated by the handle I23 for clutching the gear I26 or I2I to the shaft H5 is similar to that shown in Figs. 34 and 35.

Fig. 36 shows the reverse gear I65 between the shafts I64 and, I66. The reverse gear I51 in Fig. 1 is of similar construction. A bevel gear 435 is keyed to the shaft I64, and a bevel gear 436 turns freely on the shaft I66. A sleeve 431 splined on the shaft I66 has clutch jaws 438 adjacent either end for engaging with clutch jaws on the hubs of the bevel gears. An idler 439 meshes with the gears 435 and 436. The clutch sleeve 43'! is shifted by a yoke on a handle 440 which is similar to the handle I22 in Figs. 34 and 35.

The clutch jaws on the sleeve 43'! engage the clutch jaws on the hubs of both gears 435 and 436 at the same time when the handle 440 is in its mid position, as shown in Fig. 36. With the parts in these positions the reverse gear is locked against movement because the idler 439 prevents the bevel gears 435 and 436 from turning in the same direction, and the clutch sleeve 43I engaging both bevel gears at the same time prevents them from turning in opposite directions.

When the reverse gear is locked it prevents rotation of the shaft I64, gear I63 (Fig. l) and ring gear I60. Thus the handle 446 serves as a control lever for locking the ring gear I60 against rotation. When the clutch sleeve 434 is shifted to the right in Fig. 36, power is transmitted through the gears of the reverse gear I65, and the shafts I64 and I66 turn inopposite directions. When the clutch sleeve 431 is shifted to the left in Fig. 36, power is transmitted between the shafts I64 and I66 by the clutch sleeve, and the shafts turn in the same direction.

Figs. 37-39 show the structure for holding the arm III in position after the idler I10 has been meshed with a selected gear of the gears I61. The handle I'I2 extends through an opening in a plate 442. One edge of this opening is stepped, as shown in Fig. 39, with each step the width of the gear below it, and each step so located that the handle in rests against the step when the idler H is meshed with the gear below that step. A cover plate 444 is fastened to the plate 442 by bolts 445 extending through slots in the cover plate. There are handles 446 on the nuts of these bolts so that the nuts can be loosened whenever the cover plate 444 is to be moved. One edge of the cover plate 444 has steps which cooperate with the steps on the plate 442, as shown in Figs. 38 and 39, to hold the handle H2 and arm I'II against displacement in any direction.

When the handles 446 are turned to loosen the nuts which clamp the cover plate in position, the

, slots through which the bolts 445 extend permit the cover plate to be shifted downward in Fig. 39 so that the stepped edges move apart and the handle Hi2 can be moved into any position to mesh the idler I10 with' any gear on the shaft I66.

Figs. 40 and 41 are diagrams showing the variations in the velocity of the knife drums and knives. Assuming again for purposes of illustration that the knife drums have a circumference of 10 feet, then when cutting 12 foot lengths the drums would turn-1 A revolutions between each cut if the peripheral speed of the drums'were equal to the lineal speed of the strip. Since the shear is designed to cut on multiples of a half revolution of the knife drums, the gearing must be set to cause the drums to turn 1 or 1% revolutions while 12 feet of strip pass through the shear. The gearing between the eccentrics and feed rolls must, of course, always be set to cause the timing eccentrics to make one revolution while the length of material to be cut passes through the feed rolls. If the gear H8 (Fig. 1) is clutched to the shaft I I so that the drums make 1 revolution for each 

